id=RULE002
recipient_domain==example.org
action=size(recipient/20971520/86400/REJECT only 20mb per day for $$recipient)

Do not allow more than 20MB or 1000 recipients per day for users alice and bob:

id=RULE003
sasl_username=~/^(alice|bob)$/
action=size(sasl_username/20971520/86400/REJECT only 20mb per day for $$recipient)
id=RULE004
sasl_username=~/^(alice|bob)$/
action=rcpt(sasl_username/100/86400/REJECT only 100 recipients per day for $$sasl_username)